Absorbent articles such as diapers, sanitary napkins and the like, are used to collect bodily fluids from a person using the article during a fluid discharge. The absorbent articles are equipped with a liquid-impermeable backsheet on the outside of the article, i.e. that side of the article that faces away from a user during use, and an absorbent body placed between the liquid-impermeable backsheet and the user's body. The absorbent body is arranged to absorb the bodily discharge and the liquid-impermeable backsheet is intended to hinder the absorbed liquid in the absorbent body from leaking to the outside of the article.
It is also known to use so called breathable backsheets for absorbent articles, i.e. water vapour permeable backsheets that allows water vapour to be transported from within the absorbent article to the outside of the absorbent article via the backsheet, i.e. in the Z-direction. The breathable backsheets are intended to diminish the amount of water vapour within the article, since such water vapour may cause a too humid microclimate adjacent the skin of the user. Such humid microclimate may cause irritation on the user's skin.
One problem with breathable backsheets is the formation of condensed water vapour on the outside of the article, i.e. on the outside of the backsheet. The condensed water gives a wet and uncomfortable feel for the user. Furthermore, the condensed water may be transferred to the clothing of the user, which may develop into an unpleasant wet spot visible on the user's clothing.
A number of solutions are present in the background art, for example the use of an absorbent body on the outside of the backsheet, where the absorbent body is intended to absorb the condensed water vapour. A problem with such a solution is that the backsheet and the absorbent body become thick and uncomfortable for the user. Another problem is that the absorbent body cannot hold the liquid during high pressure, e.g. when the user is sitting down, which may cause the release of liquid from the absorbent body such that an indiscreet wet spot may appear on the user's clothing.
U.S. Pat. No. 5,814,035 shows a breathable backsheet arrangement comprising two breathable layers. The arrangement is intended to minimise the formation of condense on the outside of the backsheet. Between the layers are positioned desiccant particles adapted for drying the moist air passing through the backsheet by absorbing the water vapour in the zone between the two layers. According to U.S. Pat. No. 5,814,035, suitable desiccant particles are made from calcium chloride, super absorbent materials, silica gel or the like.
One disadvantage with the arrangement according to U.S. Pat. No. 5,814,035 is that the desiccant particles absorb water vapour whereby the backsheet arrangement increases in weight and thickness. For example, the absorbed water vapour causes the super absorbents to swell and become thick, which gives a less flexible backsheet which makes the absorbent article less comfortable for a user. Furthermore, the desiccant materials have a maximum power of absorption. When the maximum limit is reached, the desiccant particles cannot absorb any more water vapour which leads to an increased water vapour transport to the outside of the backsheet with a formation of condensed water on the outside of the backsheet as a consequence.
There is thus still a need for a breathable backsheet adapted for an absorbent article with a minimised or no formation of condensed water on the outside of the backsheet during use.